Why was Ayatollah Khomeini able to lead a successful
Islamic revolution in Iran in 1979?

Background

In 1921 Reza Khan, commander of an Iranian cossack
force, overthrew the decadent Kajar dynasty, and, as Reza Shah Pahlevi,
established the Pahlevi dynasty in 1925. During his reign, transportation
and communication systems were improved, and a program of Westernization
was begun. In 1941 Britain and the Soviet Union occupied areas of the country
to protect the oil fields from German seizure. Because of this Allied presence,
Reza Shah Pahlevi, who had been friendly to the Axis powers, abdicated.
His son, Muhammad Reza Shah Pahlevi, succeeded to the throne and adopted
a pro-Allied policy. In 1945 the Iranian government requested the withdrawal
of occupying troops, concerned that Soviet forces were encouraging separatist
movements in the northern provinces. All troops were withdrawn by
1946.

In the 1950s, a major political crisis developed
over control of the oil industry. In 1951 Muhammad Mossadegh, a militant
nationalist, became prime minister. When parliament approved a law nationalizing
the property of foreign oil companies with widespread popular support, Mossadegh
pressed the shah for extraordinary powers. The dissension between pro- and
anti-Mossadegh forces reached a climax during 1953 when the shah dismissed
the prime minister. Mossadegh refused to yield, and the shah fled to Rome.
After three days of riots, the royalists won back control of Teheran, the
shah returned, and Mossadegh was sentenced to prison. The shah then
opened negotiations with an eight-company oil consortium that guaranteed
Iran a margin of profit greater than anywhere else in the Middle
East.

Throughout the 1960s, the shah began to exercise
increasing control over the government after dissolving parliament in
1961. Programs of agricultural and economic modernization were pursued,
but the shah's Plan Organization took charge of economic development, leaving
very few benefits to reach the ordinary
citizen.

Despite growing prosperity, opposition to the
shah was widespread, fanned mainly by conservative Shiite Muslims, who wanted
the nation governed by Islamic law. They were directed, from France, by Ayatollah
Ruhollah Khomeini (Ruhollah ibn Mustafa Musawi Khomeini Hindi), a Muslim
clergyman who had been exiled in
1963.

As the Shah's regime, supported by the U.S.,
became increasingly repressive, riots in 1978 developed into a state of virtual
civil war. In early 1979 popular opposition forced the shah to leave
the country. Hundreds of the shah's supporters were tried and executed, others
fled the country, and the westernization of Iran was reversed. Khomeini,
who had returned to Iran in triumph in February 1979, presided over the
establishment of an Islamic
republic.

On 4 November 1979, after the shah had been
allowed entry into the United States for medical care, militant Iranians
stormed the US embassy in Teheran, taking 66 Americans hostage. The militants
demanded that the shah be turned over to face trial and that billions of
dollars he had allegedly took abroad be returned. Thirteen of the hostages
were soon released, but another 53 were held until an agreement was negotiated
that freed the hostages on 20 January 1981. Unable to persuade Iran
to release them, President Carter ordered a military rescue mission, which
failed, resulting in the deaths of eight American servicemen when their aircraft
collided in the Iranian desert.

In September 1980 Iraq took advantage of Iran's
internal political disputes to seize territory in the Shatt al Arab and oil-rich
Khuzestan province. The full-scale war that resulted severely reduced Iran's
oil production and disrupted its economy. The government was also beset by
unrest among ethnic minorities. The war ended with a cease-fire in 1988 and
cost the two nations an estimated 1 million dead and 1.7 million
wounded.

In 1989, Khomeini died and Hojatolislam Said
Ali Khamenei became Iran's supreme leader. Iran's relations with the West
improved, due in part to President Ali Akbar Hashemi Rafsanjani's role in
obtaining the release of Western hostages held in Lebanon. In 1993 Rafsanjani
was reelected president.

Timeline

6 June 1963, martial law ordered
as riots follow the arrest of Ayatollah Ruhollah Khomeini.

16 January 1979, shah left the
country after turmoil.

1 February 1979, revolutionary
forces under Khomeini seize power after his return to the country (He had
gone into exile after arrest in 1963.).

31 March 1979, referendum approved
the establishment of an Islamic republic with Khomeini in de facto
control.

7 April 1979, prominent Iranians
executed.

4 November 1979, Iranian militants
seized the U.S. embassy in Teheran and held sixty-six occupants hostage,
demanding the return of the shah from the U.S. After the shah's death
in 1980 in Egypt, an agreement was negotiated that freed the hostages on
20 January 1981.

2 December 1979, Khomeini became
absolute ruler for life.

27 July 1980, shah
died.

November 1980, the First Gulf
War broke out between Iran and Iraq.

WWW sites

There are a lot of materials now avaliable
online about the crisis; start by checking a major reference source
such as Brittanica, Answers.com or even wikipedia. A good
overview of the Iranian
Revolution is on the web, as well as a paper on the
religious
background of the revolution.

In retaliation for the seizure of the hostages,
President Carter,
imposed
an oil embargo on Iran on 12 November 1979. Deputy Secretary
of State Warren Christopher
briefed
the press on Iran's Release of American hostages on 21 January
1981.

Roy Mottahedeh, The Mantle of the Prophet:
Religion and Politics in Iran (1985) is a thoughtful study of the role
of Islam in Iran in the twentieth century. Another useful work is Shaul
Bakhash, The Reign of the Ayatollahs: Iran and the Islamic
Reception, rev. ed. (1990). Others include: Said Arjomand,
The Turban for the Crown: The Islamic Revolution in Iran (1988);
D. Hiro, Iran under the Ayatollas (1985); N. R. Keddie, The Roots
of Revolution: An Interpretive History of Modern Iran (1981); and
Amin Saikal, The Rise and Fall of the Shah
(1980).

On the hostage crisis in particular, see:
B. Rubin, Paved with Good Intentions: The American Experience in Iran
(1981).